Braking mechanism



July 8, 1941. .1. w. HATCH BRAKING ummmi su Filed Feb. 1:5, 1939 wNI v INVENTOR. .lwss W- fflaz'azimq m ,2

O I ATTORNEY.

Patented July 8, 1941 BRAKING MECHANISM James W. Hatch, Detroit, Mich, assig'nor to The Firestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio Application February 13, 1939, Serial No. 256,118

12 Claims.

My invention relates to a new and useful improvement in a braking mechanism adapted primarily for use on vehicle wheels and particularly adapted for use on landing wheels of an airvention;

Fig. 4 is a central sectional view through an operating part of a modified form of the mechanism;

Fig. is a central sectional view through anl3 and the flange l4 for retaining a tire in position thereon. The hub I5 is journaled on bearings it which are mounted on a stationary shaft ll. .Fixedly mounted on the shaft I1 is a hub gages so that when the nut 20 is threaded against the bearing ring 2| the bearings will be locked into position and the wheel secured journaled on the bearings. A hub cap 22 is mounted on plane. It will appear obvious, however, that the 5 the outer face of the wheel.

braking mechanism may be utilized for braking Welded or otherwise secured to the shaft ll on any rotating body. It is an object of the is a disk 23 to which the disk 24 projecting outpresent invention to provide a braking mechawardly from the hub I8 is attached by the bolts nism in which an expandable frictional member 25. The disk 24 has on its outer end an integral may be expanded through the application of channel-shaped member having side walls 26 pressure to a plurality of operable members such and 21. and a base 28 to provide a circular as small balls which are enclosed in a confined trou aped c p d Structure. A space so that upon being crowded together, they circular flange 29 extends outwardly from the may press against the expandable member and inner face of the wheel on the inner surface of force it into braking position, which is secured the brake lining 30.

It is another object of the invention t pro- Extending through and between the side walls i a breaking mechanism of thi class mu h 26 and inwardly from the outer edges thereof will be simple in structure, economical of manuare P or rivets 3l-. In the invention I use facture, compact, durable, easily and quickly a plurality o Shoes for braking purposes- These operated and highly eflicient in e, shoes comprise a box-like structure having an It is another object 'of the invention to pro- 'ereuate, face P oje t ng centrally inwardly vide a braking mechanism of thi class in which from which are the bifurcated spaced lugs 33. a plurality of separable braking shoes may be The end walls of the braking shoes are slotted expanded outwardly into braking position and as at extending o h t e ppositely in which a maximum of heat transference will disposed Slots in the Walls and be w the 1185 be effected to effect increased emciency of th 33 is a spring r 35 f m d f om flat a prin device and to provide a long life. and having the semi-circular recess 36 iormed Other Objects will appear hereinaft r, at its transverse medial line for reception of the The invention in its structure and method of P This Sp bar 35 a o P j s ou h operation will appear in the description given the angul y turned end 31 of the metallic and in which reference will be had to the accom- Shield the m c Shield 8 Ov pp the panying drawing forming a part of this specificorresponding shield of each adjacent shoe to cation and in which, form circumferentially expansible means at the i 1 i a rear l ti i partly i bases of the brake shoes. In this manner these tion; of the invention showing it applied to a shoes are mounted on the pins 3| and the Sp wheel; bar 35 which serve to normally retain the shoes Fig. 2 is a central vertical sectional view of the moved radially y into op e P ioninventlon applied to a wheel; When the shoes are pressed outwardly the outer Fig. 3 is a fragmentary central sectional view faces 32'thereof will enga e the inne face of illustrating the shoe mounting used in the in- 40 e b ake lining 30 and provide the desired frictional contact. These shield plates 38 serve to form a circular closure 'of'the space 39 in the channel positioned inwardly from these plates.

forcing the plate 40' upwardly at its free end is against which one of the bearing rings l9 enaway from the bottom 28 so as to crowd th ment or space 39. By pressing the free end of the plate 40' inwardlyrthe' space in which the balls are positioned is reduced and the balls, be-

' ing crowded together, will force the shoes outmovable inwardly and outwardly of said staso that when the rocking pressure on. the arm 7 to resume its normal position and lie flat.

upon the bottom 28. The metallic shield is associated with the shoes and their mountings together with the metallic side walls 26 and 21 and the balls 46 serve as a large heat conducting area to rapidly remove the heat away from the shoes as the same is generated.

In Fig. 4 I have shown a construction in which a nipple 49 is formed on the wall 26 through which suitable pressure may be directed against the balls 46 for crowding the same-together.

In Fig. 5 I have shown a guide boss 50 in which is'mounted a plunger 5| engageable by one end 52 of a lever rockably mounted on the pin 53 projected through the lug 54. The opposite end of the lever is connected to a rod 55 through which rocking movement may be transmitted for forcing the plunger 5| inwardly to crowd the balls when desired.

In Fig. 6 I have shown a cylinder 58 formed on one of the side walls closed by a plate 51 having a nipple 58 projecting outwardly therefrom. A bore 59 is formed in this nipple through which liquid may be delivered to effect a movement of the piston 60 which will operate as the crowding agent. In this form, also, I have shown a threaded rod 6| projectable into the space 39 which will serve as a means of adjustment, a lock nut 62 being threaded on this rod. It will be noted that in all of the forms except in the form illustrated in Fig. 1 and Fig. 2 the thrust delivered to the balls is axially of the structure and is a direct thrust by the thrust delivering agent. It is believed obvious that the part 28 may be considered a brake drum with its inner surface considered the friction surface. This 4 surface is illustrated as covered with a brake lining but it is obvious that this lining may be dispensed with if desired.

As shown in Fig. 4, the shield members 38 are of the same width as the space between the walls 26 and 21 so that this row of shield members forms a circumferential closure of the channel and together with the side walls and the part 28 the chamber 39 is formed.

With a brake constructed in this manner the various advantages are obtained and a highly efficient device provided.

Many modifications embodying in the invention herein set out will suggest themselves but it is the intention in the claims appended hereto to cover such modifications as embody the inven tion herein set forth.

What I claim as new is: v

1. A braking mechanism of the class described, comprising: a rotatable drum; a stationary member positioned within said drum and having a circular channel formed on its periphery open at the outer side and terminating adjacent the inner surface of said drum; a plurality of separate brake shoes rockably mounted in said channel adjacent the outer side thereof and radially 2,248,171 balls 46 which are positioned in the comparttionary member and adapted upon radial outward movement for frictionally engaging said brake drum; a shield member carried by each of said shoes and extending across the inner side of the shoe on which said shield member is mounted and overlapping the adjacent end of the adjacent shoe, said shields forming a closure in said channel for forming with the bottom thereof a chamber; a plurality of disconnected inter-engaging thrust members substantially filling said chamber; axially movable means for delivering a thrust to said thrust members and reducing the space in said chamber occupied by said thrust members for forcing said thrust members against the inner sides of said shoes and forcing the same radially outwardly.

2. A braking mechanism of the class described,

comprising: a rotatable drum; a stationary member positioned within said drum and having a circular channel formed on its periphery open at the outer side and terminating adjacent the inner surface of said drum; a plurality of separate brake shoes rockably mounted in said channel adjacent the outer side thereof and radially movable inwardly and outwardly of said stationary member and adapted upon radial outward movement for frictionally engaging said brake drum; a shield member carried by each of said shoes and extending across the inner side of the shoe on which said-shield member is mounted and overlapping the adjacent end of the adjacent shoe, said shieldsforming a closure in said channel for forming with the bottom thereof a chamber; a plurality of disconnected inter-engaging thrust members substantially filling said chamber; axially movable means for delivering a thrust to said thrust members and reducing the space in said chamber occupied by said thrust members for forcing said thrust members against the inner sides of said shoes and forcing the same radially outwardly and resilient means associated with each of said shoes for moving the same radially inwardly upon release of the outward thrust delivered thereto.

3. A mechanism of the class described, comprising: a rotatable brake drum; a stationary supporting member positioned in said drum and mounted concentrically thereof a circular channel-forming member on said supporting member, the channel thereof opening at the outer" side thereof; a plurality of separate circumferentially arranged, spaced.brake shoes mounted in said channel adjacent the outer side thereof and Y55 adapted for radial inward and outward movement and adapted upon radial outward pnovement for frictionally engaging said brake drum; a spring associated with each of said shoes for normallyresisting radial outward movement of the same; cooperating means carried by each of said shoes for forming with the bottom of said channel a closed chamber, said cooperating means extending circumferentially radially inwardly of said shoes; a plurality of disconnected inter-engaging thrust members positioned in said chamber and substantially filling the same; and axially movable means insertable into said chamber for occupying a portion of the same and delivering a thrust to said engagement members and forcing the same into pressing relation with said cooperating means for forcing saidshoes radially outwardly.

4. A mechanism of the class described, comprising: a rotatable brake drum; a stationary supporting member positioned in said drum and mounted concentrically thereof; a circular channel forming member on said supporting member, the channel thereof opening at the outer side thereof; a plurality of separatecircumferentially arranged spaced brake shoes mounted in said channel adjacent the outer side thereof and adapted for radial inward and outward movement and adapted upon radial outward movement for frictionally engaging said brake drum; a'spring associated with each of said shoes for normally resisting radial outward movement of the same; cooperating means carried by each of said shoes for forming with the bottom of said channel a closed chamber, said cooperating means extending circumferentially radially inwardly of said shoes a plurality of disconnected inter-engaging thrust members positionedin said chamber and substantially filling the same; and means for reducing the volume of said chamber and exerting pressure on said thrust members for forcing the same into pressing relation with said cooperating means for forcing said shoes radially outwardly.

5. A brake mechanism of the class described, comprising: a brake drum having a circular engagement surface; a braking mechanism positioned in said brake drum and comprising a stationary supporting member; a circumferential channel-bearing member on 'said supporting member, the channel thereof opening at its outer side; a plurality of independently mounted rockable brake shoes mounted in said channel adjacent the outer side thereof, said shoes being arranged in circumferentially spaced relation;

means positioned radially inwardly of said shoes for forming with the bottom of said channel a closed chamber, said means being radially movable under pressure; a plurality of separate contacting engaging members in said chamber and substantially filling the same; and axially movable means insertable into said chamber for occupying a portion of the same and reducing the space available for saidcontact members and exerting pressure on said contact members for forcing the same into ,position for moving'said shoes radially outwardly.

6. A brake mechanism comprising a rotatable drum,- a stationary member having an annular channel formed therein opening outwardly of the brake, a plurality of independent brake shoes,

means mounting said brake shoes in the outer portion of said annular channel, separate shield means associated with of said brake shoes, and overlapping the end of one of the adjacent brake shoes to form a continuous shield around saidchanneL'said shield means combininglwith the lower portions of said channel to form 'a chamber extending around said stationary member, thrust delivering means positioned in said chamber, and means for delivering a thrust to said thrust delivering means for forcing said shield outwardly.,

'7. A brake mechanism comprising a rotatable channel formed therein opening outwardly of the brake, a plurality of independent brake shoes the inner surface of each plate positioned in said channel and movable radially outwardly thereof.

9. A brake mechanism as in claim 7 in which I said means for delivering a thrust to said thrust delivering means comprises .axially movable means insertable into said channel for occupying a portion thereof and forcing said shield outwardly.

10. A brake mechanism comprising a rotatable drum, a stationary member having an annular channel formed therein opening outwardly of I the brake, a plurality of separate arcuate brake drum, a stationary member having an annular mounted in'the outer portion of said annular shoes, means mounting said brake shoes independently in the outer portion of said annular channel, separate shield means positioned radially inwardly of eachof said brake shoes and overlapping a corresponding end of one of said brake shoes immediately adjacent same to form a continuous expandible shield around said channel. thrust delivering means positioned in said channel between the base thereof and said shield means, and means for exerting a force upon said thrust delivering means to force same outwardly against said shield means, said brake shoes being separately removable from said stationary member whereby one of said brake shoes can be removed from the brake mechanism without breaking the continuous shield formed around said channel.

11. A brake mechanism as in claim 6 in which means insertable into said annular channel are provided forvarying the volume of the chamber formed to receive said thrust delivering means.

12. A brake mechanism comprising a drum, a member having an annular channel formed therein opening outwardly of the brake positioned 'within saiddrum, said drum and said member being rotatable relative to each other, a plurality of brake shoes separately mounted in said channel for radial movement relative thereto, ci-rcumferentially expansible means positioned at the bases of said brake shoes, thrust deliverin'g'means interposed between the base of said annular channel and said circumferentially expansible means, an arcuate member secured at one end thereof to the base of said annular channel, and means for moving the free portion of said arcuate member radially outwardly, said arcuate member bearing directly'upon said thrust delivering means whereby a radially outwardly 4 directed force isexerted upon said brake shoes to move them outwardly towards said drum when said arcuate member is moved outwardly relative to said channel.

' JAMES W., HATCH. 

